Sri Sri Ravi Shankar:
Yagnas are an ancient science that work on the subtle level of consciousness.
If you open a transistor, you will find a circuit diagram on a piece of metal chip. Our cell phone chips have this too. In the same way, there are certain diagrams which are there in this universe for energy to move. The ancient people knew this and they called these diagrams Yantras.
They Yantras are geometrical figures, and are a very important part of any yagna. They are used along with the five elements (Earth, Water, Fire, Air, Ether), specific chants and specific rituals to activate certain energies in the atmosphere.
Yagnas cleanse the subtle atmosphere from negative energy and infuses positivity. People throw negative thoughts and negative emotions into space, and that has to dissolve and disappear somewhere, and that’s when they use these Yantras, Mantras and Tantras in the Yagnas.
In a Yagna, many different things are done in a specifically designated manner to produce a definite effect. It is very beneficial to participate in a Yagna, and its effects are more for those who meditate. When the people who sit for the yagna and the people who are performing the yagna are both meditators then the impact is more. Sometimes people do it just as a ritual, then its impact is not that great.
There are different Yagnas for health, happiness, progress and removing obstacles in life.